Martin, 17, was shot and killed while walking home unarmed on Feb. 26, 2012 in Sanford, Fla., from a deli near his father's fiancee's house.

George Zimmerman, a volunteer neighborhood watch captain, has claimed the unarmed teen was acting suspicious and that he shot the teenager knocked him to the ground and they began wrestling over Zimmerman's gun.

Zimmerman was charged with second-degree murder and pleaded not guilty. A central part of his defense, his lawyer has said, will be Florida's Stand Your Ground law.

Earlier this month, Zimmerman's attorneys were denied a request to delay his murder trial, which is scheduled to begin in June.

The case ignited a national debate on gun control, race and Stand Your Ground laws.

Florida's Stand Your Ground law grants immunity to anyone who uses deadly force, inside or outside his home, if he can reasonably claim he was defending himself. Florida passed the law in 2005 and there are 32 states with similar laws.

Some lawmakers and civil rights groups are in an ongoing fight to have the laws repealed or changed, but so far, none of them have been repealed.